Tropospheric inhomogeneities can form a major
error source in differential synthetic aperture radar interferometry
measurements, which are used in slow-deformation monitoring.
Indeed, variations of atmospheric conditions between two
radar acquisitions produce variations in the signal path of two
images and, thus, additional fringes on differential interferograms.
These effects have a strong influence on interferograms and must
be compensated to obtain reliable deformation measurements.
This paper presents a methodological approach to reduce at both
global and local scales tropospheric contributions directly from
differential interferograms. It first requires refined knowledge of
the stable scatterers that can only be obtained from the analysis
of a large population of multitemporal interferograms. The
correction of global-scale atmospheric contribution exploits the
correlation between phase and topography. The correction of
local artifacts is based on the correlation between interferograms
containing one common acquisition. This technique is validated
on a database of 81 differential interferograms covering the
Gulf of Corinth (Greece) and used to improve the measurements
of ground deformation compared to global positioning system
measurements.